Glass surfacing apparatus



Aug. 23, 1932. J. DRAKE GLASS SURFACING APPARATUS Filed June 18, 1926 Patented Aug. 23, 1932 UNITED STATES PATENT OFFICE JOHN L. DRAKE,

OF TOLEDO, OHIO, ASSIGNOR TO LIBBEY-OWENS-FORD' GLASS COM- PANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO GLASS SURFACING APPARATUS Application filed June 18, 1926. Serial No. 116,799.

The present invention relates to glass surfacing apparatus, and has particular reference to polishing apparatus.

An important object of the invention is to rovide a process and apparatus for producmg polished glass wherein a blank is passed through a preheating temperature before it is subjected to a polishing action.

Another important object is to provide an apparatus for producing ground and polished sheet glass wherein a sheet of glass is passed through a preheating compartment to elevate the temperature of the blank before it is subjected to a polishing action.

Still another object of the invention is to provide a process and apparatus for producing ground and polished sheet glass wherein a sheet of glass is ground, after which the sheet is passed through a preheating chamber to elevate the temperature thereof, the sheet then being subjected to the action of polishing members, the temperature of the sheet, after it passes through the preheating chamber, being substantially of the same temperature as the temperature ordinarily gengrated by the action of the polishing memers.

A further object of the invention is to provide a process and apparatus wherein a sheet of glass is moved continuously and progressively' beneath a plurality of grinding and polishing units, the apparatus including a chamber arrangedbetween the grinding units and the polishing units through which the sheet passes, where it is subjected to a heating action to elevate the temperature of said blank before it is subjected to the action of polishing units, the sheet passing from the heated chamber to and under a series of polishing units, the polishing units being arranged in a manner that a hood may be positioned over the sheet to prevent a sudden change in temperature of the sheet as it passes from under one unit to another.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the drawing wherein like numerals are employed to designate like parts throughout the same,

'with a plurality of grinding and polishing heads or units. Although this system is here illustrated, it is to be understood that the invention can be applied equally as well in the other types of surfacing machines.

It has been customary in the prior art to place a sheet of glass on a table movable beneath a series of surfacing units, the sheet being held in place by means of plaster of Paris or the like. During the grinding operation the sheet of glass does not become heated because abrasive suspended in relatively cool water is continuously applied on the sheet between the same and the grinding head. In the prior art constrnctions,after the sheet has been suitably ground on one side, it is cleaned, replastered if necessary, and then passed under a series of polishing heads. I have noticed that the sheet passes under several of the heads before any noticeable polishing takes place, indicating to me that there is heat present before any polishing takes place. Due to the fact that the sheet is exposed to the atmosphere, in the prior art structures, between adjacent polishing units, it is essential that the temperature of the sheet is kept below the danger point, which is the point where the sheet is liable to crack or break when the cooler atmosphere of the room contacts therewith. It may be that the heat generated is a result of the polishing action, or it may be that the polishing action is dependent upon the heat generated, but in any event the heat and polishing seem to be coupled together in the production of polished glass. 4

In the present invention the sheet, after it has been ground, is passed through a heated chamber so that the temperature of the sheet will be raised preferably to a temperaturesubstantially the same as the temperature of the sheet when it is subjected to the action of the polishing units. In addition to the preheating chamber, I preferably provide chambers between adjacent polishing units, similar to the construction set forth and claimed in m copending application, Serial No. 107,904, filed May 10, 1926, and which has matured into Patent No. 1,714,301, issued May 21, 1929.

In the drawing, the numeral 10 designates a sheet of glass which is supported upon a moving table 11. The table, and sheet 10 which is ordinarily cemented thereon by means of plaster of Paris, is movable under the grinding heads 12 and the polishing heads 13.

The grindin may be accomplished by some suitable a rasive such as sand, emery, or garnet. The grinder head 12, shown in the drawing, designates the last of a series of such heads. After the sheet of glass has passed from under the last grinder, it is preferably Washed by means of a spray or the like, and is then passed through the preheat ing chamber 14, which may be formed by means of a hood 15 as shown in Figs. 2 and 3. The hoods 15 are preferably arranged over the sheet in a manner that the sheet 10 may be heated with little effort. In Fig. 2, the hood is illustrated as being heated by means of hot water or steam passing through the said head by means of the conduit 16. In Fig. 3, a gas burner 17 is shown heating the table 11. It is, of course, to be understood that any form of heating means may be employed such as gas and electric heaters. The hood designated in its entirety by the numeral 14 in Fig. 1, and more specifically by the numeral 15 in Figs. 2 and 3, may be formed from a suitable metal. The construction of the hood is such that a temperature control medium may be circulated therethrough as clearly illustrated in the drawing, while the conduits 16 are provided to permit the introduction and removal of the temperature control medium to and from the hood. The hoods may be supported on the base members 18.

The sheet is subjected to a temperature in. the compartment 14, which is preferably substantially the same temperature as the temperature generated by the polishing units 13. The polishing units 13 ordinarily comprise a plurality of movable felt covered blocks,

. which, together with their movement and the action of a suitable polishing medium such as rouge, change the surface produced by the grinders 12 from an opaque surface to a polished transparent surface.

The numeral 17 designates a suitable hood arranged between the compartment 14 and the first of the series of units 13, the hood 17 being shaped to prevent exposure of the sheet to room temperatures when passing from the hood to the polishing unit. The numerals 18 designate suitable hoods arranged between the polishing units and are similar to the structures set forth and claimed in my copending application mentioned above.

By employing the invention set forth, a sheet of glass may be polished much more rapidly than heretofore because the sheet does not have to move under several polishing units before any polishing action takes place, and secondly because the heat generated by the polishing units can be greater than heretofore in view of the fact that the sheet is protected from drafts and relatively cooler temperatures by means of the hoods. If it is desired, the sheet may be passed through an annealing leer after it has been polished to gradually reduce it to room temperatures.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In sheet glass surfacing apparatus, a plurality of grinding members and a plurality of polishing members, means for moving a sheet of glass under said members, and means for heating the sheet as it passes from the grinding members to the polishing memers.

2. In sheet glass surfacing apparatus, a plurality of grinding members, means for passing a sheet of glass in contact therewith to grind the same, a heated compartment through which the sheet is passed after it has been ground, and a plurality of polishing members arranged in proximity to the heated compartment whereby the sheet of glass, after it has been heated, may be passed in contact with the polishing members.

3. A continuous system for producing surfaced glass, comprising a plurality of grinding machines, a heated compartment, and a plurality of polishing machines, the heating compartment being interposed between the grinding machines and the polishing machines.

4:. In sheet glass surfacing apparatus, grinding means, means for passing a sheet of glass in contact therewith to grind the same. heating means in proximity to which the sheet is passed after it has been ground, and polishing means arranged in proximity to the heating means whereby the sheet of glass, after it has been heated, may be placed in contact with the polishing means.

5. The process of producing surface glass, consisting in passing a sheet of glass beneath grinding means", then, after the sheet has been ishing operation.

ground, passing it in proximity to heating means in a manner to heatthe surface of the sheet, and then removing the sheet from the heating means and polishing said sheet.

6. The process of producing surface glass, consisting in passing a sheet of glass beneath a series of grinding means, then passing the sheet through a heated compartment to heat the same, and then passing the sheet under a series of polishin means.

7. The process o? producing plate glass, consisting in first grinding a glass sheet, then polishing the same, and in heating said sheet between the grinding and polishing thereof to a temperature substantially the same as the temperature generated'during the pol- 8. The process consisting in first grinding a glass sheet, then polishing the same, in heatin said sheet-between the grinding and polis ing thereof to a temperature substantially the same as the temperature generated during the polishing operation, and in maintaining the temperature of the glass during polishing substantially constant. 7

9. In sheet glass surfacing apparatus, grinding means, polishing means spaced from the grinding means, means for passing the glass in contact first with the grinding means to grind the sheet and then with the polishing means to polish the same, and means for heating the sheet as it is being passed from the grinding means to the polishing means to a temperature substantially the same as the temperature generated by said polishing means during the polishin operation.

10. In sheet glass sur aclng apparatus, polishing means spaced means for passing grinding means, from the grinding means,

the glass in contact first with the grinding means to grind the sheet and then with the polishing means to polish the same, means for heating the sheet as it is bein passedfrom the grinding means to the po ishing means to a temperature substantially the same as the temperature generated by said polishing means during the polishing operation, and means for malntaining the temperature of the glass during the polishing thereof substantially constant.

Signed at Toledo, in the county of Lucas, and State of Ohio, this 16th day of June,

JOHN L. DRAKE.

of producing plate glass, 

